GB2341824A

GB2341824A - Reinforced frame joint for a vehicle trailer

Info

Publication number: GB2341824A
Application number: GB9922077A
Authority: GB
Inventors: Wilfried Wasserfuhr; Gunter Dowe; Bernd Rhein; Reinhold Pittius
Original assignee: BPW Bergische Achsen KG
Current assignee: BPW Bergische Achsen KG
Priority date: 1998-09-22
Filing date: 1999-09-17
Publication date: 2000-03-29
Anticipated expiration: 2019-09-17
Also published as: FR2783487A1; GB2341824B; GB9922077D0; DE19843396C1

Abstract

A floor assembly for a vehicle trailer, such as a caravan, comprises a frame to which an axle (4) of the trailer is attached and which comprises at least one longitudinal strut (6) and at least one towing strut (12) which extends from the front of the frame as an extension of the longitudinal strut. The two struts are connected together with means such as a protrusion on the end of the longitudinal strut being inserted into the end of the towing strut, and there then being a reinforcement member located beneath the joint. The reinforcement member (29) is attached beneath the towing strut (12) and extends beneath the frame construction so as to be attached to the underside of the longitudinal strut. The reinforcement member is preferably a downwardly open U-section and may be attached by means of a screw connector. The whole frame may be protected against corrosion, and also may have transverse members with openings through which the longitudinal member may pass so as to reduce the height of the framework (see figure 4). There may also be a thin plate beneath the frame and which has cutouts for the trailer wheels.

Description

1 2341824 FLOOR ASSEMBLY FOR A VEHICLE TRAILER. PREFERABLY A CARAVAN The

invention relates to a floor assembly for a vehicle trailer, preferably a caravan, comprising, a frame construction to which an axle of the vehicle trailer is attached and which comprises a longitudinal strut, a towing strut which extends from the front of the frame construction as an extension of a longitudinal strut and which provides a connection between a towing coupling of the vehicle trailer and the longitudinal strut.

The invention is based on the object of developing a floor assembly having the abovementioned features in such a manner that the floor assembly can be individually adapted to the load situations to be expected while underway without changes being made to the frame construction. 15 The achievement of this objective is characterised by a reinforcement which is attached to the underside of the towing strut, which extends until it reaches under the frame construction and which is attached there to the longitudinal strut. The invention is based on the fact that in the case of a caravan, the statics and strength 20 of the frame construction of the floor assembly can be configured without great outlay in such a manner that a sufficient account is taken of all of the driving situations conceivable in practice and hence of the load situations. However, the weakest element in the dynamic system of movement of a caravan remains that part of the 2 draw bar which is formed by one or more towing struts and extends between the towing coupling and the vehicle trailer body. It is at this point that the highest tension, compression and bending loads occur while underway. It is therefore proposed according to the invention, just in this region, to carry out adaptation to the load conditions to be expected, by a respective reinforcement being attached to the underside of the or each towing strut. The or each reinforcement extends until it reaches under the frame construction and is attached there to the associated longitudinal strut of the frame construction. The selection of this reinforcement therefore follows the load situation, to be expected individually of the vehicle trailer, influenced, for example, by the weight thereof or the height of its body. In particular, it is possible to provide floor assemblies which are standardized and can therefore be produced cost-effectively on a relatively large scale for various model series, and then to adapt said floor assemblies to the load conditions to be expected individually by in each case attaching a suitably dimensioned reinforcement.

According to a refinement it is proposed to use a section as the reinforcement, which section is simultaneously screwed to the towing strut and to the longitudinal strut.

In a further refinement it is proposed that a plate be attached to the underside of the frame construction, which plate covers the underside of said frame construction, and that that section of the reinforcement which extends under the frame construction 3 bears against the underside of the plate. The plate, which is preferably essentially rectangular and on both sides of the vehicle can be provided with cutouts for the wheels, helps to avoid admission of dirt and moisture in the floor assembly, as a result of which corrosion of the metal sections of the frame construction is avoided.

In a refinement of the floor assembly it is proposed that that section of the reinforcement which extends under the frame construction be screwed to the associated longitudinal strut, the screw passing through an opening in the plate. In this manner, the attachment of the reinforcement simultaneously helps in the securing of the plate downwardly covering the frame construction, which simplifies the production of the floor assembly.

It is furthermore proposed that the towing struts which extend between the towing coupling and the frame construction be separable from the longitudinal struts, and the separating point be situated in front of a first transverse strut of the frame construction.

This solution makes it possible for, on the one hand, the frame construction and, on the other hand, the towing struts and the remaining parts of the draw bar to be produced separately. It is thus, for example, of advantage to provide the frame construction with a cataphoretically applied dip coating for treatment of its surfaces.

In the event of the towing struts being able to be separated from the longitudinal struts, this can take place with the towing struts removed, as a result of which the 4 construction is reduced in size and even shorter dipping tanks suffice in order to carry out the dip coating. It is also of advantage when keeping in storage if the floor assembly can be kept relatively short as a consequence of removable towing struts.

Of course, the above-mentioned advantages can also be obtained if there is only a single towing strut which can in this case be inserted into a longitudinal strut of the frame construction, which longitudinal strut is arranged centrally in the centre of the vehicle.

The longitudinal strut and towing strut are preferably in each case configured by rectangular metal sections having essentially the same cross section, in which case there is inserted into the metal section of the longitudinal strut a connecting section which partially protrudes at the front from the longitudinal strut, fits flush into that end of the towing strut which is open to the rear and can be locked therein, preferably by means of a screw connection which simultaneously passes through the connecting section and towing strut.

According to a further preferred embodiment of the floor assembly, the frame construction consists of longitudinal struts and transverse struts, said struts in each case being metal sections whose overall heights partially overlap in the vertical direction. At the crossing points, the transverse struts are provided, transversely to their length, with recesses through which the longitudinal struts pass, the longitudinal struts being designed such that their entire cross section is continuous at the crossing points.

The following is a more detailed description of embodiments of the invention, by way of example, reference being made to the appended drawings in which:

Figure I is a side elevation of a floor assembly for a caravan together with a towing coupling and an axle construction; Figure 2 shows the floor assembly of Figure 1 in a plan view; Figure 3 shows the floor assembly of Figure 1, which is simplified in parts as compared with Figures 1 and 2, in a perspective view obliquely from above; Figure 4 shows, in a perspective representation, a crossing point between a longitudinal strut and a transverse strut of the floor assembly shown in Figures 1 to 3, which is denoted in Figure 2 by IV; Figure 5 shows, in reduced individual representation, various cross-sections through 20 the floor assembly according to Figures I to 3, the plane of section represented being denoted in Figure 2 by V-V; 6 Figure 6a shows a section in the plane V1a-VIa of Figure 2; Figure 6b shows a section in the plane VIb-VIb of Figure 2; Figure 6c shows a section in the plane VIc-VIc of Figure 2; Figure 7 shows a section in the plane VII-VII of Figure 2 with a representation of a screw connection between a longitudinal strut of the floor assembly and a reinforcement attached below the longitudinal strut, and 10 Figure 8 shows, in cross-section, an alternative screw connection to that of Figure 7. Figures 1, 2 and 3 show a floor assembly 1, a coupling device 2 with a coupling part 3 serving for connection to a towing vehicle, and also an axle construction 4 of a 15 caravan. Finally, four crank supports 5 can also be seen, these serving to support the caravan when it is parked. The filling and covering layer of the floor assembly, and also the side walls, end walls and roof of the caravan body and the wheels are not shown. 20 As best seen in Figures 2 and 3, the floor assembly includes a frame construction having two longitudinal struts 6, which essentially extend in the direction of travel, 7 and also four transverse struts 7, 7a, 7b which extend transversely to the direction of travel. Here, the transverse strut 7a is the front transverse strut, the transverse strut 7b is the rear transverse strut, and between them there are also situated two further transverse struts 7. All of the transverse struts 7, 7a, 7b are welded at crossing points 8 to the longitudinal struts 6. All of the struts consist of multi-edged steel plate.

The axle construction 4 includes an axle tube 9, which is attached to the underside of the longitudinal struts 6 via a U-section. The axle construction also has two links 10 that carry axle stubs and brakes, here in the form of drum brakes 11.

As shown in Figures 2 and 3, each longitudinal strut 6 has a rear portion that extends parallel to the direction of travel and a front portion that extends forwardly and inwardly from the corresponding rear portion so that the two front portions run towards each other in a truncated V-shape.

The floor assembly 1 also comprises two towing struts 12 that extend from the front of the frame construction to the towing coupling 2. Each towing strut 12 extends from, and in the same direction as, a respective one of the front portions of the longitudinal struts 6. Each towing strut 12 can be separable from the associated longitudinal strut 6.

8 All of the transverse struts 7, 7a, 7b, the longitudinal struts 6 and the towing struts 12 are metal sections, of which some are open and some closed.

Figure 4 reveals details of a crossing point 8 between one of the longitudinal struts 6 and one of the transverse struts 7 of the frame construction. The longitudinal strut 6, which is composed here of a main section 13 and an additional section 14 that is attached parallel to the main section 12, is designed such that it is continuous, i.e. has no particular mechanical machining work, in the region of the crossing point 8. In contrast, the transverse strut 7 is provided in the region of the crossing point 8 with a cutout or recess 15 through which the longitudinal strut 6 passes. It can in particular be seen in Figure 4 that the recess 15 extends from below into the cross- section of the transverse strut 7, for which purpose the two vertical walls 16 of the transverse strut 7 are provided with corresponding openings whose contour is matched to the external contour of the crossing longitudinal strut 6. The transverse strut 7 according to Figure 4 is configured as a metal section which is hat shaped in cross section (as shown in Figure 4) and, in addition to the two vertical walls 16, also has an upper, horizontal wall 17 and two lower, horizontal walls 18 which protrude to respective sides of the transverse strut 7. The two lower horizontal walls 18 together are at least as wide as the upper horizontal wall 17. In order to form the recess 15, the lower, horizontal walls 18 are also provided with corresponding incisions. Furthermore, tabs 19 are bent to the side out of the vertical walls 16. These tabs 19 make it possible for the 9 transverse strut 7 to be welded to the longitudinal strut 6 over a relatively large area. A further weld may be drawn at the point at which the interruption in the lower, horizontal walls 18 meets the longitudinal strut 6.

Figure 4 furthermore clearly reveals that the longitudinal strut 6 passes through the correspondingly cutout transverse strut 7. Only the upper, horizontal wall 17 of the transverse strut 7 is of continuous design, i.e. is not interrupted by the recess 15. This is of importance since the greatest tensile stresses in the transverse strut 7 occur on the upper side thereof, i.e. in the plate thickness of the upper horizontal wall 17. At that 10 point the transverse strut 7 should not be weakened. In the exemplary embodiment according to Figure 4, the two-part longitudinal strut 6 consists of two rectangular C sections whose openings point towards the centre of the frame construction. Since the longitudinal strut 6 virtually passes through the transverse strut 7 and the overall heights of the two struts partially overlap, the frame construction of the floor assembly 15 can be realised with a very small overall height yet with sufficient strength and a low weight. If, in contrast, the struts were welded such that they lie one on top of the other in the crossing region, virtually twice the overall height would disadvantageously ensue. 20 Figure 5 shows a longitudinal section through the floor assembly at various points along the length of the floor assembly. The transverse struts 7, 7a, 7b are each metal sections which are hat-shaped in cross section, the transverse strut 7 being configured and arranged in the same way as is shown in Figure 4 but the front transverse strut 7a and the rear transverse strut 7b are arranged the other way round with an upwardly pointing opening. The transverse struts 7a and 7b are specially shaped sections whose upper, horizontal walls 20 can be extended to one side and in this manner form supports 21 for part of the caravan body, for example for an extended floor plate or for the rear wall of the caravan. Also, the front and rear transverse struts 7a and 7b, which are specifically designed for their additional function, are welded via tabs 19 to the two longitudinal struts 6, as has already been explained with reference to Figure 4 for the transverse struts 7. The transverse struts 7, 7a, 7b may, as shown in Figure 3, be provided with openings 23 in order to reduce weight. The same is also true of the longitudinal struts.

The clearances which arise in the box-type product of the longitudinal struts 6 and transverse struts 7, 7a, 7b are provided with fillings. Finally, the floor of the caravan, for example a plywood panel which can be walked on, is situated on top.

A thin plate 26, shown as a heavy line in Figures 5, 6c and 7, is attached to the underside of the floor assembly. The essentially rectangular plate 26 is provided with cutouts 27 for the wheels. Finally, the floor assembly 1 furthermore includes edge sections 28a along the side edges, which edge sections produce the connection 11 between the frame construction and the side walls of the caravan.

For the purposes of providing reinforcement in the always particularly critical region between the towing coupling 2 and the frame construction, there are two reinforcements 29 in the form of U-shape metal sections which, starting from the front region of the underside of the frame construction, extend until they reach under the towing struts 12. The reinforcements 29 can best be seen in Figures 1 and 3, with the plate 26 having been omitted in Figure 3 for reasons of clarity. Each reinforcement 29 consists of a U-section which tapers slightly towards both ends, is downwardly open and is placed from below against a respective towing strut 12 and an associated longitudinal strut 6. The length of each reinforcement 29 is such that it starts below the corresponding towing strut 12 close to the towing coupling 2 and extends until it reaches under the frame construction of the floor assembly, preferably until it approaches or reaches the point at which the front and rear portions of the associated longitudinal strut 6 meet. Each reinforcement 29 is attached by means of screw connections both to the underside of the associated longitudinal strut 6 and also to the underside of the associated towing strut 12, so that the bending moments which are effective in the region of the towing struts 12 can be absorbed at the same time by the reinforcements 29. The selection and dimensioning of the reinforcements 29 can therefore be matched individually to the particular size and weight of the caravan, as a result of which standardisation during series manufacture of the floor assemblies is 12 possible.

At the points which are identified in Figure 2 by the reference number 30, i.e. directly in front of the frontmost transverse strut 7a, the towing struts 12 can be separated from the associated longitudinal struts 6.

As Figures 6a, 6b, 6c and 7 show, in order to obtain this ability to separate, the longitudinal strut 6 can be inserted by its front end, which is slightly reduced in size in cross section, into a rearwardly open end of the associated towing strut. For this purpose, at 30 a connecting section 31 is inserted into the longitudinal strut 6, which connecting section partially protrudes at the front from the longitudinal strut 6. This connecting section 31 fits flush into the rearwardly open end 32 of the towing strut 12 and can be locked therein by means of a screw connection which passes simultaneously through the connecting section 31 and towing strut. It is adequate for the longitudinal strut 6 to be able to be connected fixedly to the connecting section 31 which in turn releasably holds or secures the towing strut.

Details of this screw connection are explained below with reference to the Figure 7, Figure 7 clearly showing the screw connection of reinforcement 29 to the longitudinal strut 6 in the region of the frame construction. The longitudinal strut 6 is a rectangular C section into which there is vertically inserted a supporting sleeve 33 through which 13 a screw 34 passes. The supporting sleeve 33 can be attached in the section of the longitudinal strut 6 by means of individual welding points, in order thereby to be secured in place. The screw 34 rests with its flat head 35 on the upper side of the longitudinal strut 6 and extends through the longitudinal strut and supporting sleeve 33 into the section of the reinforcement 29. At that point a nut 36 having a plain washer 37 is placed onto the thread of the screw. In order to be able to tighten the nut 36 without having to fix the head 35 of the screw 34 by a locknut, just below the head there is situated a multi-edged section 38 which passes in a positively locking manner through an opening, which is correspondingly multi-edged, in the upper, horizontal wall 39 of the longitudinal strut 6. By means of this refinement, the attachment of the reinforcement 29 to the longitudinal strut 6 is very easily possible by a single person, since first of all the screws 34 can be inserted into the frame construction, then the reinforcement 29 fitted from below, and finally the plain washer 37 and nut 36 have to be placed on and tightened. Fixing the screw 34 by a locknut at the same time is not required.

Figure 8 shows an alternative embodiment to Figure 7, in which instead of a means of securing against rotation in a positively locking manner by a multi- edged section, the nut 36 of the screw connection is welded fixedly on a plate 39a on the upper, horizontal wall 39. The plate 39a prevents the longitudinal strut 6 from being weakened while the nut 36 is welded on. To install the reinforcement 29, a screw is 14 then guided from below through the reinforcement 29, longitudinal strut 6, supporting sleeve 33 and plate 39a into the net 36 and is then tightened. Installation by a single person is possible in this case too. The longitudinal strut 6 in this case is a closed section. The supporting sleeve 33 is fixed in the section by crimping on both sides.

Figure 7 reveals that the attachment of the reinforcement 29 takes place with the plate 26 already fitted, i.e. the plate 26 is wedged between the longitudinal strut 6 and the reinforcement 29 as the screw connection is tightened. For this purpose, the plate 26 is provided with corresponding openings for the passage of the screw 34.

The attachment which is explained with reference to Figures 7 and 8 with regard to the reinforcement 29 has a corresponding use in the attachment of the axle construction 4. As Figure 3 reveals, the axle tube 9 of the axle construction 4 is attached to a downwardly open U-section 40 by welding. This U-section 40 is then attached in the same manner from below to the longitudinal strut 6, as is shown in Figures 7 and 8 for the reinforcement 29, preferably including the wedging of the plate 26 between the U-section 40 and underside of the longitudinal strut 6.

The frame construction of the floor assembly can be coated with zinc. However, the frame construction is preferably surface-treated as a whole by means of cataphoretic dip coating (cataphoretic dip coating process). This takes place with the towing struts 12 and reinforcements 29 removed, as a result of which the construction is reduced in size and likewise relatively short dipping tanks suffice in order to carry out the dip coating. The towing struts 12 are preferably zinc-coated.

It will be appreciated that the floor assembly can be varied. For example, there need not be two longitudinal struts 6 and two towing struts 12. There could be one of each strut 6, 12. Alternatively, there could be three or more longitudinal struts 6 and a corresponding number of towing struts 12. 10 16

Claims

Floor assembly for a vehicle trailer, preferably a caravan, comprising, a frame construction to which an axle of the vehicle trailer is attached and which comprises a longitudinal strut, a towing strut which extends from the front of the frame construction as an extension of the longitudinal strut and which provides a connection between a towing coupling of the vehicle trailer and the longitudinal strut, and a reinforcement which is attached to the underside of the towing strut, which extends under the frame construction and which is attached thereunder to the longitudinal strut.
2. - Floor assembly according to claim 1, characterised in that the reinforcement is a profiled section which is screwed simultaneously to the towing strut and to the longitudinal strut.
3. Floor assembly according to claim 1 or claim 2, characterised in that a plate is attached to the underside of the frame construction, which plate covers the underside of said frame construction, and in that that section of the reinforcement which extends under the frame construction bears against the underside of the plate.
4. Floor assembly according to claim 3, characterised in that the plate is essentially rectangular and on each side of the vehicle trailer is provided with a 17 respective cutout for one or more wheels.
5. Floor assembly according to either of claims 3 or 4, characterised in that that section of the reinforcement which extends under the frame construction is screwed to the longitudinal strut, the screw passing through an opening in the plate.
6. Floor assembly according to any one of the preceding claims, characterised in that the towing strut can be separated from the longitudinal strut, and in that the separating point is situated in front of a first transverse strut of the frame construction.
7. Floor assembly according to claim 6, characterised in that the longitudinal strut and the towing strut are rectangular metal sections having essentially the same cross section, and in that inserted into the metal section of the longitudinal strut is a connecting section which partially protrudes at the front from the longitudinal strut, fits into that end of the towing strut which is open to the rear and can be locked therein, preferably by means of a screw connection which simultaneously passes through the connecting section and towing strut.
8. Floor assembly according to any one of the preceding claims, characterised in that the frame construction consists of longitudinal struts and transverse struts, and said struts are elongated metal sections whose overall heights partially overlap in the 18 vertical direction, and in that at the crossing points the transverse struts are provided, transversely to their lengths, with recesses through which the longitudinal struts pass, the longitudinal struts being designed such that their entire cross-section is continuous at the crossing points. 5
9. Floor assembly according to any one of the preceding claims, characterised in that the frame construction is coated with a cataphoretic dip coating.
10. Floor assembly substantially as hereinbefore described with reference to the drawings.